Design of porphyrin-based conjugated microporous polymers with enhanced singlet oxygen productivity

Novel non-toxic materials with antimicrobial surfaces are needed for medicinal applications. Potential alternatives for bacterial inactivation include materials that produce singlet oxygen, O-2((1)Delta(g)), a short-lived, highly oxidative, and cytotoxic species. We synthesized a promising group of materials, porphyrin-based conjugated microporous polymers (CMPs), which effectively generate O-2((1)Delta(g)) under visible light irradiation. CMPs were rationally designed and synthesized to maximize O-2((1)Delta(g)) production. A strategy based on three-dimensional frameworks allowed the immediate environment of the porphyrin units to be tuned and their structure-property relationships to be elucidated. We investigated the photophysical and photochemical properties of the frameworks and compared them with the properties of porphyrin-based CMPs and metal-organic frameworks. In general, the O-2((1)Delta(g)) production activity of the CMPs correlated with neither the surface area nor with the pore volume. The novel CMPs displayed high O-2((1)Delta(g)) production, were stable in organic solvents, and did not undergo measurable photobleaching.